Carbon dioxide removal

Looking out across the Southern Ocean near Antarctica, I can see whales and seabirds diving in and out of the water as they feed on sea life in the lower levels of the food web. At the base of this food web are tiny phytoplankton – algae that grow at the ocean surface, taking up carbon from the atmosphere through photosynthesis, just as plants on land do. Because of their small size, phytoplankton are at the mercy of the ocean’s swirling motions. They are also so abundant that the green swirls are often visible from space. Typically, phytoplankton remain near the surface of the ocean. Some may slowly sink to depth because of gravity. But in the turbulent Drake Passage, a 520-mile-wide (850 km) bottleneck between Antarctica and South America, something unusual is happening, and it has an impact on how the ocean takes carbon dioxide – the main driver of global warming – out of the atmosphere. A satellite image capt...

Heat waves, droughts and extreme weather are endangering people and ecosystems somewhere in the world almost every day. These extremes are exacerbated by climate change, driven primarily by increasing emissions of greenhouse gases that build up in the atmosphere and trap heat at the Earth’s surface. With that in mind, researchers are exploring ways to pull carbon dioxide out of the atmosphere and lock it away – including using the ocean. But while these techniques might work, they raise serious technical, social and ethical questions, many of which have no clear answers yet. We study climate change policy, sustainability and environmental justice. Before people start experimenting with the health of the ocean, there are several key questions to consider. Ocean carbon dioxide removal 101 The ocean covers about 70% of the planet, and it naturally takes up carbon dioxide. In fact, about a quarter of human-produced carbon dioxide ends up in the ocean. Ocean carbon di...